function [num,pro] = pro_heisexinbiao()
P=ones(1,70);
p=0.8;
for i=1:70
    k=max(fix((i-35)/5),0);
    P(i)=min(p*2^k/100,1);
end
Pi=ones(1,70);a=1;q=0;
for k=1:70
    Pi(k)=a*P(k);%恰好第K次抽中概率
    q=q+Pi(k)*k;%出货期望抽数
    a=a*(1-P(k));
end
plot(Pi);
format long
num = q;
pro = 1/q*100;
format default